RECTUM
- RECTUM
- FEATURES
- place between
- sigmoid canal and anus
- distension
- desire to defecate
- shape
- not straight
- curved anteroposterior direction
- absent
- sacculations , appendices epiploicae , taenia
- SITUATION
- posterior part of pelvis
- infront of 3 pieces of sacrum
- EXTENT
- begins at
- level of S3 vertebra
- from recto-sigmoid junction
- ends at
- ano-rectal junction
- a little below the tip of coccyx
- DIMENSIONS
- 12 cm long
- upper part
- 4 cm diameter same as sigmoid colon
- lower part
- dilated to form rectal ampulla
- COURSE AND DIRECTION
- runs
- downward and backward
- downward
- downward and forwards
- curvatures
- anteroposterior curves
- sacral flexure of rectum
- follows concavity of sacrum and coccyx
- perineal flexure of rectum
- backward bend at anorectal junction
- lateral curves
- upper lateral curve
- convex to the right
- middle lateral curve
- convex to left and most prominent
- lower lateral curve
- convex to right
- RELATIONS
- Peritoneal relations
- upper 1/3rd covered with peritoneum
- infront
- sides
- middle 1/3
- only infront
- lower 1/3
- devoid of peritoneum
- lies below
- rectovesical pouch in males
- rectouterine pouch in females
- Visceral relations
- anteriorly
- in males
- upper 1/3 is related to
- rectovesical pouch
- with coils of intestine and sigmoid colon
- lower 1/3
- base of urinary bladder , terminal parts of ureters
- seminal vesicle , deferens ducts and prostrate
- in females
- upper 1/3 is related to
- rectouterine pouch
- with coils of intestine and sigmoid colon
- lower 1/3rd
- lower part of vagina
- posteriorly
-
- lower 3 pieces of sacrum , coccyx , anococcygeal ligament
- piriformis , coccygeus and levator ani
- median sacral , superior rectal and lower lateral sacral vessels
- sympathetic chain and ganglion impar
- pelvic splanchnic nerves
- anterior primary rami of s3,s4,s5
-
- MUCOSAL FOLDS
- longitudinal folds
- transitory
- transverse folds or houston's valves or plicae transversales
- permanent
- types
- first tranverse fold
- upper end of rectum
- second transverse fold
- upper end of rectal ampulla
- third transverse fold
- projects from left wall
- FUNCTIONAL PARTS OF RECTUM
- sigmoid colon is the faecal reservoir
- rectum is a temporary reservoir
- Arterial supply
- superior rectal artery
- Middle rectal artery
- Median Sacral artery
- Venous supply
- Superior rectal vein
- Middle rectal vein
- Median sacral vein
- Lymphatic drainage
- Upper half of rectum
- along superior rectal vessels to inferior mesenteric nodes
- through pararectal and sigmoid nodes
- Lower half of rectum
- Middle rectal vessels to internal iliac nodes
- Nerve supply
- Supports of rectum
- Pelvic floor formed by levator ani muscles
- fascia of waldeyer
- lateral ligament of rectum
- rectovesical fascia of denonvilliers
- Pelvic peritoneum
- Perineal body with its muscles
- Sacral flexure
- Lateral flexures
- Superodextral lateral flexure; superior lateral flexure
- Intermediosinistral lateral flexure; intermediate lateral flexure
- Inferodextral lateral flexure; inferior lateral flexure
- Transverse folds of rectum Kohlrauschi
- Rectal ampulla
- Muscular layer; muscular coat
- Longitudinal layer
- Rectococcygeus
- Anorectoperineal muscles; recto-urethral muscles
- Rectoperinealis; recto-urethralis superior
- Anoperinealis; recto-urethralis inferior
- Rectovesicalis
- Circular layer
- Lateral ligament of rectum; rectal stalk
Discussion